Thanks for the responses.
Have spent many hours with the angle grinder and various wire wheels trying to remove as much of the flaking and surface rust as realistically possible without dropping the rear diff, exhaust, etc, etc.
I know if I start dropping the diff and other components i’ll open a can of worms that will lead to way more than i’m looking to take on.
A bit short on time (and getting a bit lazy) so began to think maybe just Fluid Film but as NOBB brought up, once Fluid Film is applied it’s tough to clean and prep for POR-15.....excellent point!
Just want to be done with this so I can get started on valve cover & LBJ replacement......more fun!